1. Field of the Invention
The present invention relates to a data transmitter apparatus and a data receiver apparatus between which desired data of, e.g. a moving image, is transferred.
2. Description of the Prior Art
As digital communication technologies being advanced, a variety of transmitter apparatus have been developed for transferring digital data of a moving image through a transmission channel. FIG. 5 shows one such prior art arrangement for transmitting moving image data through a digital transmission channel, in which a transmitter 501 in a data transmitter apparatus 1 is coupled by a digital transmission channel 502 to a data receiver apparatus 2. The data receiver apparatus 2 comprises a clock reproducer 503 and a receiver 504.
In operation, the moving image data in digital form is transmitted as a stream of bits from the transmitter apparatus 1 via the transmission channel 502 to the clock reproducer 503 in the receiver apparatus 2. At the clock reproducer 503, a clock signal synchronized with the bit stream is reproduced from the transmitted data. The transmitted or input data is processed by the receiver 504 with synchronization with the clock signal to reconstruct an original image.
In such a manner, moving image data can be transferred through the digital transmission channel.
However, the processing of the input image data at the receiver apparatus 2 shown in FIG. 5 is controlled by the clock signal which is synchronous with a clock signal for data transmission through the transmission channel 502. More particularly, a frame synchronizing signal for reproducing the moving image is timed with the transmission clock signal. Accordingly, a frame synchronizing signal at the transmitter apparatus 1 has to be synchronous with the transmission clock signal.
When the transmission channel 502 is connected to a plurality of asynchronous motion image data output apparatuses, its clock signal can be synchronized with only one of the apparatuses, thus preventing the remaining apparatuses from being simultaneously operated.